From 32e2070f56731da80cf73fc662ac31f72febb42a Mon Sep 17 00:00:00 2001
From: Benjamin Bouvier <benjamin@bouvier.cc>
Date: Tue, 10 Dec 2024 11:45:53 +0100
Subject: [PATCH] refactor(ffi): use a bool instead of an option to make the
 API less awkward

By default, the event cache store will be disabled. If disabled, it will
clean all the events in the cache store; most of the time this will do
nothing, since the store will not even be filled with any event data, so
it would be cheap to do. If some data was filled in the cache store
before, then it would be cleared after the cache store has been
disabled.

This makes a less awkward API than the previous one, where `None` and
`Some(false)` carried different semantics.
---
 bindings/matrix-sdk-ffi/src/client_builder.rs | 40 ++++++++++---------
 1 file changed, 21 insertions(+), 19 deletions(-)

diff --git a/bindings/matrix-sdk-ffi/src/client_builder.rs b/bindings/matrix-sdk-ffi/src/client_builder.rs
index 189b9e48b..d08023339 100644
--- a/bindings/matrix-sdk-ffi/src/client_builder.rs
+++ b/bindings/matrix-sdk-ffi/src/client_builder.rs
@@ -273,7 +273,9 @@ pub struct ClientBuilder {
     decryption_trust_requirement: TrustRequirement,
     request_config: Option<RequestConfig>,
 
-    use_event_cache_persistent_storage: Option<bool>,
+    /// Whether to enable use of the event cache store, for reloading events
+    /// when building timelines et al.
+    use_event_cache_persistent_storage: bool,
 }
 
 #[matrix_sdk_ffi_macros::export]
@@ -304,7 +306,7 @@ impl ClientBuilder {
             room_key_recipient_strategy: Default::default(),
             decryption_trust_requirement: TrustRequirement::Untrusted,
             request_config: Default::default(),
-            use_event_cache_persistent_storage: None,
+            use_event_cache_persistent_storage: false,
         })
     }
 
@@ -313,13 +315,15 @@ impl ClientBuilder {
     /// This is a temporary feature flag, for testing the event cache's
     /// persistent storage. Follow new developments in https://github.com/matrix-org/matrix-rust-sdk/issues/3280.
     ///
-    /// To enable the persistent storage: call this with `true`.
+    /// This is disabled by default. When disabled, a one-time cleanup is
+    /// performed when creating the client, and it will clear all the events
+    /// previously stored in the event cache.
     ///
-    /// To explicitly disable a previously-enabled persistent storage, call this
-    /// with `false` to clear the previous content in storage.
+    /// When enabled, it will attempt to store events in the event cache as
+    /// they're received, and reuse them when reconstructing timelines.
     pub fn use_event_cache_persistent_storage(self: Arc<Self>, value: bool) -> Arc<Self> {
         let mut builder = unwrap_or_clone_arc(self);
-        builder.use_event_cache_persistent_storage = Some(value);
+        builder.use_event_cache_persistent_storage = value;
         Arc::new(builder)
     }
 
@@ -645,19 +649,17 @@ impl ClientBuilder {
 
         let sdk_client = inner_builder.build().await?;
 
-        if let Some(val) = builder.use_event_cache_persistent_storage {
-            if val {
-                // Enable the persistent storage \o/
-                sdk_client.event_cache().enable_storage()?;
-            } else {
-                // Get rid of the previous events, if any.
-                let store = sdk_client
-                    .event_cache_store()
-                    .lock()
-                    .await
-                    .map_err(EventCacheError::LockingStorage)?;
-                store.clear_all_rooms_chunks().await.map_err(EventCacheError::Storage)?;
-            }
+        if builder.use_event_cache_persistent_storage {
+            // Enable the persistent storage \o/
+            sdk_client.event_cache().enable_storage()?;
+        } else {
+            // Get rid of all the previous events, if any.
+            let store = sdk_client
+                .event_cache_store()
+                .lock()
+                .await
+                .map_err(EventCacheError::LockingStorage)?;
+            store.clear_all_rooms_chunks().await.map_err(EventCacheError::Storage)?;
         }
 
         Ok(Arc::new(